Integer signedness error in the amd64_set_ldt function in sys/amd64/amd64/sys_machdep.c in FreeBSD 9.3 before p39, 10.1 before p31, and 10.2 before p14 allows local users to cause a denial of service (kernel panic) via an i386_set_ldt system call, which triggers a heap-based buffer overflow.
The product performs operations on a memory buffer, but it reads from or writes to a memory location outside the buffer's intended boundary. This may result in read or write operations on unexpected memory locations that could be linked to other variables, data structures, or internal program data.